whatever remains, however improbable, must be the truth."

It is a truth universally acknowledged that Jane Austen doesn't do servants or children except when they serve her purposes - one instance being Margaret in the present work. However, in Ch.16 she surely pushes this to the extreme. The three sisters (yes, it is the three of them including Margaret, although you'd hardly know it) are out walking when they see in the distance

They argue about whether or not it is Willoughby until they come to

Note that the whole time, from when they are too far away to determine the nature of this figure to when they are only 30 yards away from him, it is only one figure that they see. It turns out to be Edward. He

....who just appears out of nowhere. Now, we know this to be impossible. Therefore, by applying Sherlock Holmes' most famous dictum as given in the header of this message, we arrive at the improbable but obviously true conclusion that he is a wizard from Hogwarts School of Witchcraft and Wizardry, and has Apparated there, or has used the Floo network or a portkey.